Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262890AbUDTMnZ (ORCPT ); Tue, 20 Apr 2004 08:43:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262864AbUDTMnH (ORCPT ); Tue, 20 Apr 2004 08:43:07 -0400 Received: from mail.gmx.de ([213.165.64.20]:50826 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S262873AbUDTMlM (ORCPT ); Tue, 20 Apr 2004 08:41:12 -0400 X-Authenticated: #4512188 Message-ID: <40851A6E.8050409@gmx.de> Date: Tue, 20 Apr 2004 14:41:18 +0200 From: "Prakash K. Cheemplavam" User-Agent: Mozilla Thunderbird 0.5 (X11/20040413) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Jeff Garzik CC: Denis Vlasenko , Konstantin Sobolev , Justin Cormack , Ryan Geoffrey Bourgeois , Kernel mailing list , linux-ide@vger.kernel.org Subject: Re: poor sata performance on 2.6 References: <200404150236.05894.kos@supportwizard.com> <1082039593.19568.75.camel@lotte.street-vision.com> <200404151848.05857.kos@supportwizard.com> <200404152030.51052.vda@port.imtp.ilyichevsk.odessa.ua> <407F315E.2000809@pobox.com> In-Reply-To: <407F315E.2000809@pobox.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2188 Lines: 64 Jeff Garzik wrote: > Denis Vlasenko wrote: > >> On Thursday 15 April 2004 17:48, Konstantin Sobolev wrote: >> >>> On Thursday 15 April 2004 18:33, Justin Cormack wrote: >>> >>>> On Thu, 2004-04-15 at 15:26, Konstantin Sobolev wrote: >>>> >>>>> On Thursday 15 April 2004 18:00, Justin Cormack wrote: >>>>> >>>>>> hmm, odd. I get 50MB/s or so from normal (7200, 8MB cache) WD disks, >>>>>> and Seagate from the same controller. Can you send lspci, >>>>>> /proc/interrupts and dmesg... >>>>> >>>>> >>>>> Attached are files for 2.6.5-mm5 with highmem, ACPI and APIC turned >>>>> off. >>>> >>>> >>>> ah. Make a filesystem on it and mount it and try again. I see you have >>>> no partition table and so probably no filesystem. This means the block >>>> size is set to default 512byte not 4k which makes disk operations slow. >>>> Any filesystem should default to block size of 4k, eg ext2. >>> [snip] >>> So first time it gave the same loosy 27 MB/s and subsequent tests give >>> pretty good 68 MB/s! Why? >> >> >> >> Time to CC ide/libata/block layer folks >> >> Jeff Garzik >> libata man > > > > It seems like the situation is already resolved, to me. > > When you mount a filesystem, it changes the default block size (512 or > 1024) to the filesystem block size, normally 4096. This would certainly > increase the throughput. Hi Jeff, it is NOT resolved: I just tried libata again, and I can observe the same behaviour: I just did a "cat /dev/sda >/dev/null" and watched gkrellm2 showing the throughoutput. The first tiem I do the cat I only got about 27mb/s, no matter how ong I waited, but all subsequent cat gave me about >60mb/s. So there is a tiny bug in libata, I guess, as when using the siimage.c ide driver, already the first cat gives me maximum throughoutput. I am using 2.6.5-mm4 based kernel. Filesystems were mounted/ I didn't change anything between first and secound cat. bye, Prakash - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/